Now showing items 1-20 of 293

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      The Crystal and Molecular Structure of 2-Formylpyridine Selenosemicarbazone  [Article]

      Conde Amiano, Alejandro; López Castro, Amparo; Márquez Delgado, Rafael (International Union of Crystallography, 1972)
      The structure of 2-formylpyridine selenosemicarbazone, SeN4CTH8, has been determined from threedimensional X-ray photographic data. The crystals are monoclinic, space group P2t/e, with unit-cell dimensions a=9.320, b=6-524 ...
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      The Crystal and Molecular Structure of 1-p-Chlorophenyl-4-(tt-a-erythrofuranosyl)-4-imidazoline-2-thione  [Article]

      Pérez Garrido, Simeón; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1974)
      The title compound, CISOsN2C~sH~3, the definitive formula of which has been established by X-ray structural analysis, is orthorhombic, space group P2~2121 with a= 7.806 (5), b= 29.417 (13) and c= 5-921 (5) A, Z--4. The ...
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      The Crystal Structure and Molecular Conformation of 3,7-Dichlorophenoselenazine  [Article]

      Bernier, F.; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1974)
      The crystal structure of SeC12NCI2H7 has been solved by Patterson and Fourier methods and refined to an R of 7-5 % by full-matrix least-squares methods. The unit cell is orthorhombic, with a-- 7-995 (3), b = 23.808 (1), ...
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      Molecular Packing in Crystals of Phenoselenazine  [Article]

      Villares Durán, María del Pilar; Jiménez Garay, Rafael; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1976)
      The crystal structure of phenoselenazine was solved by molecular-packing analysis. Trial models of the rigid molecule were oriented and positioned in the Cheshire cell. The refinement was carried out by structure-factor ...
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      The Crystal and Molecular Structure of 4-Formylimidazoline-2-thione  [Article]

      Conde Amiano, Alejandro; Moreno, E.; Márquez Delgado, Rafael (International Union of Crystallography, 1977)
      The title compound is monoclinic, space group P2 Jc, with a = 4.020 (4), b = 21.491(3), c = 7-410 (4) ,4,, fl = 124.1 (5) °, Z = 4. The structure was solved by Patterson-function and heavy-atom methods from diffractometer X-ray ...
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      Fluage de monocristaux de NiO  [Article]

      Cabrera Cano, J.; Domínguez Rodríguez, Arturo; Márquez Delgado, Rafael; Castaing, Jean (European Physical Society (EPS), 1978)
      NiO single crystals have been subjected to constant-load compressive creep along (100). Stresses between 50 MPa and 120 MPa and temperatures between 950 °C and 1 200 °C were studied. The activation energy observed suggests ...
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      The Conformation and Crystal Structure of meso-2,10-Dimethyl- 3,1 l-dimethoxycarbonyl- 1,6,9,13-tetraoxadispiro[4.2.4.2]tetradeca-2,10-diene  [Article]

      Conde Amiano, Alejandro; Moreno, E.; Márquez Delgado, Rafael (International Union of Crystallography, 1979)
      The crystal and molecular structure of the title compound, C16H20Os, has been determined by singlecrystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2t/c with two molecules in a cell of ...
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      Plastic deformation of CoO single crystals  [Article]

      Castaing, Jules; Spendel, M.; Philibert, Jean; Domínguez Rodríguez, Arturo; Márquez Delgado, Rafael (EDP Sciences, 1980)
      Constant strain rate compressions along < 001 > have been performed on CoO single crystals (ε ∼ 6 x 10-5 s-1). Yield stresses and work hardening rates have been measured between 77 K and 1 400 K; CoO is very strong when ...
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      Structure and Molecular Conformation of l-(4-Acetyl-5-methyl-2-furyl)- 1,3-dideoxy-3-nitro-fl-D-xylopyranose  [Article]

      Conde Amiano, Alejandro; Moreno, E.; Márquez Delgado, Rafael (International Union of Crystallography, 1980)
      The crystal structure of C I2HIsNO7 has been determined at room temperature. Crystals are tetragonal, space group P432~2, Z = 8, with a -- 12.039 (1), c = 17.979 (4)A. 1304 observed reflexions contributed to the ...
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      The Structure of l-Phenyl-4,5-(l,2-D-glucofurano)imidazolidin-2-one  [Article]

      Conde Amiano, Alejandro; Bernier, F.; Márquez Delgado, Rafael (International Union of Crystallography, 1980)
      The crystal structure of Cl3Ht6N20 5 has been solved by direct methods. Crystal data are a -- 9.033 (1), b -- 10.097 (1), c -- 7.155 (1)A, fl= 105.92 (1) °, Z -- 2, space group P21 (from statistics). The final R value ...
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      Deformation of MgO by Vickers microindentation tests  [Article]

      Giberteau, F.; Domínguez Rodríguez, Arturo; Márquez Delgado, Rafael; Castaing, Jules (EDP Sciences, 1982)
      Vickers microhardness tests have been performed at room temperature on (100), (110), and (111) MgO faces for various orientations of the pyramid diagonal. The indentations may be deformed probably because of cracking. ...
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      Kinetics of desorption from a heterogeneous surface  [Article]

      Córdoba Zurita, Antonio; Luque Palomo, José Juan (American Institute of Physics Publising LLC, 1982)
      Mathematical equations governing kinetics of desorption from heterogeneous surfaces are derived from a master equation with the assumption that only nearest-neighbor adatoms interact. A number of cases are analyzed: random, ...
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      Structure of l'-(p-Bromophenyl)-3'-ethyl- 1',3', 4',5'-tetrahydro- 1,2-dideoxy-D-glycero- L-gluco-heptofuranoso[ 1,2-d]imidazole-2'-thione,* C16H21BrN205 S  [Article]

      Estrada de Oya, María Dolores; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1983)
      M,=433.3, orthorhombic, P2,2~2,, a= 8.466 (2), b .... 27. 136 (5), c - 7.776 (5) A, V = 1786(1)A3, Z=4, D,,,= 1.60(l),Dx= 1.61Mgm -3, Mo Ka, 2 = 0.7107 A, a = 2.42 mm-', F(000) = 888, 300 K, R =0.045 for 1 196 observed ...
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      Lattice-Energy Calculations on Phenothiazine and Phenoselenazine Modifications  [Article]

      Estrada de Oya, María Dolores; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1983)
      Lattice-energy calculations in the atom-atom potential approach have been performed for observed and isostructurally derived hypothetical forms of phenothiazine and phenoselenazine compounds. Energy minimizations with ...
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      Structure of 4-(~-D-Erythrofuranosyl)-3-methyl- l-(p-tolyl)-4-imidazoline-2-thione Monohydrate, C 15H18N203S.H20  [Article]

      Criado Vega, Alberto; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1983)
      Mr=324.4, orthorhombic, P212t2 ~, a= 32.150(5), b=10.215(1), c=4.805(1)A, V= 1578.0 (4)/~3, Z = 4, D x = 1.36 Mg m -a, 2(Cu Ka) = 1.5418A, #=1.953mm -1, T=300K, final R= 0.050 for 1361 observed [I>2tr(I)] independent ...
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      Pure diffusional creep of NiO polycrystals  [Article]

      Jiménez Melendo, Manuel; Cabrera Cano, J.; Domínguez Rodríguez, Arturo; Castaing, Jules (European Physical Society (EPS), 1983)
      Compressive creep testing of polycrystalline NiO has been performed in air and argon, at temperatures between 1 100 and 1 500 °C (0.61 to 0.79 TM) under loads corresponding to initial applied stresses from 6 to 90 MPa. ...
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      Lattice Dynamics and Thermal Crystallographic Parameters in Phenothiazine  [Article]

      Criado Vega, Alberto; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1984)
      A computer program has been developed to study the lattice dynamics of molecular crystals in the harmonic approximation with the external Born-yon KS.rm~n formalism and an atom-atom potential function. Dispersion curves ...
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      Structure of l-(p-Ethoxyphenyl)-1,3-dihydro-3-phenyl-2H-benzimidazole-2-thione, C2IHlaN2OS  [Article]

      Criado Vega, Alberto; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1984)
      Mr=346-4, orthorhombic, P212121, a= 7.600(1), b= 11.132(2), c=20.767 (3)A, v= 1756.9(5)A 3, z=4, Dx=1.31Mgm -3, 2(CuKct) =.1.5418/k, /~= 1.67mm -1, F(000)=728, T= 300 K. Final R = 0.049 for 1531 observed independent ...
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      Structure of l'-(p-Bromophenyl)-3'-ethyl- 1',3t,4',5 t -tetrahydro- 1,2-¢~• deoxy-D-glyeero-Dgu/ a-heptofuranoso[ 1,2-d]imidazole-2'-thione,* C16H21BrN2OsS  [Article]

      Estrada de Oya, María Dolores; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1984)
      M r = 433.3, monoclinic, P21, a = 6.924 (3), b=8.661 (1), c=15.039(3)A, #=96.92(3) ° , v= 895.3 (4) A a, Z= 2, D, = 1.598 (5), Dx= 1.607 Mg m -a, Mo Ka, 2 = 0.7107/k, # = 2.42 mm -1, F(000) = 444, T = 300 K, R = 0.039 ...
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      First- and Second-Order Thermal Diffuse Scattering (TDS) Intensity in Molecular Crystals: Influence on Crystal Structure Parameters  [Article]

      Criado Vega, Alberto; Conde Amiano, Alejandro; Márquez Delgado, Rafael (International Union of Crystallography, 1985)
      First- and second-order thermal diffuse scattering (TDS) intensities are calculated in the long-wave approximation allowing for dispersion (LWD) in monoclinic phenothiazine from polarization vectors and lattice-mode ...